Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Porous carbon materials have a variety of industrial applications, including applications as catalyst supports, electrodes for batteries and fuel cells, gas separation membranes, and filter media in water purification. One example of a porous carbon material is porous carbon hollow spheres, which are generally considered to be mechanically strong, good conductors of electricity, and have large surface areas for maximum possible contact with target components. Accordingly, the porous carbon hollow spheres can be useful in a wide range of industrial applications such as absorbents, hydrogen storage materials, rubber additives, catalyst supports for fuel cells, lubricants, and so on. In particular, porous carbon hollow spheres can provide shorter transportation pathways than their solid counterparts, and can be used, for example, as catalyst support materials and anode materials in lithium batteries.
Considerable efforts have been devoted to the design and manufacture of porous carbon hollow spheres. Their wide range of commercial applications has also demanded reliable and effective ways for their production. A number of approaches have been developed to synthesize porous carbon hollow spheres, for example, shock-compression techniques, shock-wave techniques, pyrolysis of core-shell latex, pyrolysis of colloid particles with core-shell structure, and solvothermal synthesis. While these approaches have resulted in porous carbon hollow spheres having acceptable thermal stability and carbon yield, they have been reported to require rigorous reaction conditions, expensive apparatus, or lack of structural control over resulting porous carbon hollow spheres. Additionally, the porous carbon hollow spheres resulting from these approaches may often be damaged easily and/or have inconsistent and heterogeneous particle sizes. Therefore, there is a need for simple, efficient and scalable methods for preparing porous carbon hollow spheres.